package demo6;

/**
 * 最长回文子序列
 */
public class test5 {
    public int longestPalindromeSubseq(String s) {
        // 创建dp表
        int n = s.length();
        int[][] dp = new int[n][n];

        for (int i = n-1; i >= 0; i--) {
            dp[i][i] = 1;
            for (int j = i+1; j < n; j++) {
                if (s.charAt(i) == s.charAt(j)) {
                    dp[i][j] = dp[i+1][j-1] + 2;
                } else {
                    dp[i][j] = Math.max(dp[i+1][j], dp[i][j-1]);
                }
            }
        }
        return dp[0][n-1];
    }
}
